1. Field of Invention
The present invention relates to a method of sequencing data inside the memory of an optical scanning device. More particularly, the present invention relates to a method of sequencing image data inside the memory of an optical scanner.
2. Description of Related Art
FIG. 1 is a block diagram showing the structural connection of various components inside a conventional optical scanning device. As shown in FIG. 1, the optical scanning device includes a charge-coupled device (CCD) 110, a multiplexer 120, an amplifier 130, an analogue-to-digital converter 140 and a buffer memory unit 150. In a scanning operation, the charge-coupled device 110 scans the brightness level of a scan object and converts the brightness level into an analogue voltage signal. The analogue voltage signal is output to the amplifier 130 according to the color sequence. The amplifier 130 amplifies the analogue voltage signal and passes the amplified signal to the analogue-to-digital converter 140. The analogue-to-digital converter 140 converts the amplified analogue voltage signal to a digital voltage signal and stores it inside the buffer memory unit 150.
According to the aforementioned data output and conversion system, if the line difference between sequential sensing rows for each color in the charge-coupled device 110 is k and the number of pixels is n, the digital voltage signals inside the buffer memory unit 150 are stored in a manner shown in FIG. 2. As shown in FIG. 2, Rij represents the brightness level of red color in the ith column and the jth pixel, Gij represents the brightness level of green color in the ith column and the jth pixel and Bij represents the brightness level of blue color in the ith column and the jth pixel.
In a conventional scanning system, the data stored up inside buffer memory unit 150 may be processed in two possible schemes. The data inside the buffer memory unit 150 may be directly output to a host computer or the data may be processed so that the color of various pixels are rearranged before outputting. Although the buffer memory unit 150 may output data a lot faster if the former scheme is used, necessary processing of image data inside the host computer is greatly increased. On the other hand, although the amount of processing inside the host computer is very much simplified in the latter scheme, data outputting rate from the buffer memory unit 150 slows down considerably. In other words, conventional image data sequencing methods lead to either post-processing complications or a slow down of the data transfer rate from the memory unit to the host system.